Masked TGF-β Polypeptides for Epitope-Specific T-Cell Modulation
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Solution Overview
Problem
Current approaches to regulating transforming growth factor beta (TGF-β) action are limited in their ability to provide epitope-specific and selective modulation of T-cell responses, particularly in the context of autoimmune diseases and immune dysregulation disorders.
Innovation Solution
Development of T-cell modulatory antigen-presenting polypeptides (TMAPPs) that incorporate a masked TGF-β sequence, allowing for reversible masking and chemical conjugation of epitopes, enabling targeted presentation to T-cell receptors (TCRs) and modulation of T-cell responses through the use of additional immunomodulatory domains (MODs).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If current approaches to regulating TGF-β action are used, then TGF-β action can be regulated, but epitope-specific and selective modulation of T-cell responses cannot be achieved
Solution Approach 1:
The polypeptide is divided into distinct functional domains: an MHC class II binding domain for epitope presentation, a TGF-β sequence for immunomodulation, and a masking sequence for controlled activation. This segmentation allows each domain to perform its specific function independently while contributing to the overall epitope-specific T-cell modulation capability.
Solution Approach 2:
The polypeptide combines multiple functions into a single molecule: it acts as an MHC class II binder for epitope presentation, contains a TGF-β sequence for T-cell modulation, and includes a masking sequence for controlled activation. This multi-functionality enables the single polypeptide to achieve epitope-specific modulation that previous separate approaches could not accomplish.
2Reliability
If TGF-β sequences are made active, then T-cell modulation can occur, but specificity and selectivity for target T cells is lost
Solution Approach 1:
The TGF-β sequence is pre-masked by the masking sequence in the constructed polypeptide, preventing premature activation. The polypeptide is designed to be stable and specific in its inactive state, then activated only when bound to the correct epitope-MHC complex on the target T cell, ensuring both effectiveness and specificity.
Solution Approach 2:
The masking sequence acts as an intermediary that controls the activation state of the TGF-β sequence. It prevents premature interaction between TGF-β and T cells while allowing controlled activation upon epitope-specific binding, thereby maintaining both modulation effectiveness and target specificity.
3Adaptability or versatility
If masked TGF-β sequences are incorporated into polypeptides, then reversible masking is achieved, but chemical conjugation sites need to be added
Solution Approach 1:
The polypeptide merges multiple functional elements into a single integrated structure: the MHC class II binding domain, the TGF-β sequence, the masking sequence, and the chemical conjugation site. This consolidation allows the polypeptide to achieve reversible masking while providing sites for epitope conjugation, without requiring separate components for each function.
4Productivity
If epitopes are conjugated to MHC molecules, then T-cell presentation can occur, but controlled and selective delivery to target T cells is limited
Solution Approach 1:
The epitope is pre-conjugated to the MHC class II binding domain in a controlled manner using chemical conjugation sites. The polypeptide is designed to present this epitope specifically to T cells with matching TCRs, and the TGF-β sequence is pre-masked to prevent premature activation, enabling both efficient presentation and selective delivery.
Solution Approach 2:
The MHC class II binding domain acts as an intermediary that specifically binds the conjugated epitope and presents it to the T cell receptor. This intermediary mechanism ensures that the epitope is delivered selectively only to T cells with the correct TCR specificity, while the masked TGF-β sequence provides controlled activation upon successful recognition.
Data Source
AI summary
The present disclosure provides antigen presenting polypeptide comprising a TGF-β MOD that is reversibly masked and acts as a TGF-β receptor agonist. The antigen presenting polypeptides comprising one or more chemical conjugation sites for incorporation of, for example, epitope containing polypeptides. The present disclosure provides nucleic acids comprising nucleotide sequences encoding antigen-presenting polypeptides comprising one or more chemical conjugation sites, as well as cells genetically modified with the nucleic acids. The antigen-presenting poly peptides and their epitope conjugates are useful for modulating the activity of a T-cell, and accordingly, the present disclosure provides methods of modulating activity of a T-cell in vitro and in vivo as a method of treatment of diseases and disorders including autoimmune diseases, allergies, GVHD, HGVD, and metabolic disorder.